The broad goals of this research is to test the hypothesis that the function, development, and pathobiology of the corneal stroma or any other connective tissue is intimately associated with and dependent on the biochemical composition, their macromolecular interactions and the regulation of corneal matrix morphogenesis. A. Matrix Protein Characterization and Intermolecular Interactions Hypothesis: Type XII collagen plays an important role in maintaining proper fibril spacing during corneal morphogenesis by interacting with fibrillar collagens, proteoglycans and type VI collagen filaments in the interfibrillar space. Specific aim A1 is: To characterize, localize, and determine the interactions of type XII collagen in normal vs. healing cornea. Hypothesis: Type VI collagen is bound to corneal proteoglycans (decorin and lumican) directly or indirectly through other proteins. Specific aim A2 is: To analyze macromolecular interactions of type VI collagen with corneal proteoglycans by affinity co-electrophoresis, photoactivated cross-linkers, and rotary shadowing/electron microscopy. Hypothesis: A newly discovered corneal extracellular matrix protein, 'Betaig-h3', bound to type VI collagen, interacts with proteoglycans and type XII collagen in the stroma. Specific aim A3 is: To characterize a new corneal extracellular matrix protein, 'Betaig-h3' by molecular biological, biochemical, and ultrastructural analyses. B. Regulation of Corneal Matrix Morphogenesis Hypothesis: Metalloproteinases (MMPs) in healing and developing cornea are similar in types and distribution but are reduced in activity. Specific aim B1 is : To determine the types and activity of MMPs in developing cornea by zymography, and determine the distribution of MMP mRNA in these tissues by in situ hybridization. Hypothesis: Corneal endothelial cells participate in the deposition of stromal-type extracellular matrix in scar tissue. Specific aim B2 is: To determine, by in situ hybridization and immunohistochemistry, the capability of endothelial cells in culture to synthesize type XII collagen and decorin. Hypothesis: Specific inhibition or diminution of proteoglycan or collagen synthesis during morphogenesis of ECM results in matrix abnormalities indicative of the function of the affected macromolecules. Specific aim B3 is: To develop an experimental system which would allow determination of the function of specific types of extracellular matrix macromolecules.